The field of the disclosure relates generally to stator vane assemblies for rotary machines and more particularly, to a bushing for use within a stator vane assembly.
At least some known rotary machines include a plurality of compressor stages that each include a row of stator vanes that direct air flow downstream towards a corresponding row of rotor blades. In at least some known rotary machines, at least some of the compressor stator vanes are rotatably coupled about a longitudinal vane axis that extends generally radially outward from the centerline of the rotary machine. The angular orientation of such “variable” stator vanes, relative to the airflow through the compressor, is adjustable to facilitate improved performance at a plurality of operating conditions.
At least some known variable stator vanes include a trunnion that extends through an opening defined in a casing of the compressor, and a generally annular bushing between the trunnion and the opening. The bushing facilitates decreasing friction between, and wear on, the trunnion and the casing. However, over time, at least some known bushings eventually require replacement due to operational wear. Typically, access to an interior of the casing and, in some cases, removal of a rotor of the rotary machine, is necessary to remove and replace such known bushings. Such required disassembly increases the time and costs associated with to replacing the bushings.